Function renderAssetPreviewThreadSafe

src/python/lfs/py_rendering.cpp:376–420

        }

        [[nodiscard]] std::optional<core::Tensor> renderAssetPreviewThreadSafe(
            const std::string& path,
            const int width,
            const int height,
            const float focal_length_mm,
            const glm::mat3* rotation = nullptr,
            const glm::vec3* translation = nullptr) {
            auto invoke_render = [&]() -> std::optional<core::Tensor> {
                return renderAssetPreviewOnViewerThread(path, width, height, focal_length_mm, rotation, translation);
            };

            auto* const viewer = get_visualizer();
            if (!viewer || viewer->isOnViewerThread()) {
                return invoke_render();
            }
            if (!viewer->acceptsPostedWork()) {
                return std::nullopt;
            }

            auto promise = std::make_shared<std::promise<std::optional<core::Tensor>>>();
            auto future = promise->get_future();
            auto completed = std::make_shared<std::atomic_bool>(false);

            auto finish = [promise, completed](std::optional<core::Tensor> result) mutable {
                if (!completed->exchange(true)) {
                    promise->set_value(std::move(result));
                }
            };

            const bool posted = viewer->postWork(vis::Visualizer::WorkItem{
                .run =
                    [path, width, height, focal_length_mm, rotation, translation, finish]() mutable {
                        finish(renderAssetPreviewOnViewerThread(path, width, height, focal_length_mm, rotation, translation));
                    },
                .cancel =
                    [finish]() mutable {
                        finish(std::nullopt);
                    }});
            if (!posted) {
                return std::nullopt;
            }

            nb::gil_scoped_release release;
            return future.get();
        }

        [[nodiscard]] std::optional<glm::mat3> tensorToVisualizerRotation(const PyTensor& py_tensor) {
            const auto& tensor = py_tensor.tensor();